Emil mihsbach and anton groeschel



(No Model.)

E. MIHSBAOH & A. GROBSC-HEL.

HOT AIR ENGINE.

[Wren [22 25 720 6 CZn/m weacie UNITED STATES PATENT EricE.

EMIL llIIHSBAGH AND ANTON GROESOHEL, OF CINCINNATI, OHIO, ASSIGNORS TOTHE FOUNTAIN MACHINE COMPANY, OF SAME PLACE.

HOT-AIR ENGINE.

SPECIFICATION forming part of Letters Patent No. 566,785, datedSeptember 1, 1896.

Application filed August 28, 1895. Serial No. 580 750. N mod l-l To aZZwhom it may concern.-

Be it known that we, EMIL MIHsBAoH and ANTON GROEsGHEL, citizens of theUnited States, and residents of Cincinnati, Hamilton county, State ofOhio, have invented new and useful Improvements in Hot-Air Engines andwe do declare the following to be a full, clear, and exact descriptionof the invention, such as will enable others skilled in the art to whichit appertains to make and use the same, attention being called to theaccompanying drawings, with the reference-numerals marked thereon, whichform a part of this specification.

This invention relates to improvements in hot-air engines, a class ofmachines or motors in which a piston is reciprocated by the expansiveforce of hot air, such force acting usually only in one direction, whilea flywheel, assisted more or less by the outer atmosphere, assists thereturn of the piston. The same air is used over again, being alternatelyheated and cooled, as well as compressed within a cylinder wherein it isconfined.

The features of our invention consist particularly of means whereby thepressure of the hot air at the end of the working stroke is quicklyrelieved from in front of the piston to permit and facilitate thelatters immediate return.

Other features pertain to certain details of the construction, whichwill be explained at the proper time.

In the following specification, and particularly pointed out in theclaim at the end, is found a full description of our invention, itsoperation, parts, and construction, which latter is also illustrated inthe accompanying drawings, in which- Figures 1 and 2 are sideelevations, partly in section and taken at right angles to each other,the first showing the power-piston at its lowest, the second at itshighest, position. Fig. is a sectional view similar to Fig. 1, but withthe piston in its highest position. Fig. 4 shows the constructionwhereby the lower or displacer piston is operated.

The air-cylinderis, for convenience in manufacture, preferablyconstructed in two parts, the lower part 8 of which is screwed to theupper part 9 at 10. Forthe purpose of heating the air quickly, We havefound copper to be the best material for the lower part 8, andparticularly for the bottom thereof, against which the heat is applied.This latter may come from any source, and for the smallersized enginesgas is the most convenient. In this case a gasolene-bnrner 11 is shownwithin a jacket 12, which surrounds it and the lower part of thecylinder to prevent too rapid radiation of the heat. Vv ithin thecylinder is the power-piston 13 and the displacerpiston 14, each ofindependent stroke. The latter is below the former and does notcompletely fit the inner bore of the cylinder, but is sufiicientlysmaller to permit the air to pass from one end to the other. Itspiston-rod, consisting of a sleeve 15, surrounding a stem 16, whichscrews into the upper end of piston 14, connects by a link 17 to an arm18, fast on a rock-shaft 19, supported in bearings 20.

Rigidly secured to the outer end of rock-shaft 19 is another arm 21,which by link 22 connects to a wrist or crank pin 23 of fly-wheel 24.This latter and another fly-wheel 25 sit on the driving-shaft 26,supported in bearings 27 and provided midway with a crank 28, which by aforked link 29 connects it to piston 13. At their highest positions theopposing surfaces of the pistons practically meet, while at their lowestpositions at the end of the downstroke they are about farthest apart,from which it follows that the stroke of the lower or piston 14 islonger than the stroke of the upper piston, for which reason it mustnecessarily travel faster in order to be in time with the other pistonof shorter stroke.

The operation, the principle of which is not considered broadly new anddoes not form the leading feature of this invention, is briefly asfollows: The displacer-piston 14 on its downst-roke transfers thepreviously-heated air below it between its upper end and thepower-piston 13, after which the two pistons move up together, the lowerpiston moving faster and closing up rapidly the space between the two.The impetus which the upper piston thus receives forms the live or powerstroke of the same. The position of the parts at the beginning of thisstroke is shown in Fig. 1, while Figs. 2 and 3 show their position atthe end of the same stroke. At the end of this stroke the temperature ofthe air has become lower, partly by reason of being more remote from theheat, as well as by reason of a water-jacket 31, which surrounds theupper part 9 of the cylinder, wherebyit also contracts in volume'andpermits the pistons to descend, the same being carried down principallyby the force of the fly-wheels. Meanwhile during this upstroke the airdisplaced between the two pistons has passed downagain below piston 14and into the hottest part ofthe cylinder to'be reheated. As Will be seenby the positions of the cranks, the two pistons do not simultaneouslyarrive at their highest and lowest positions respectively, but the loweror displacer piston 14 is given aproper-l'ead, corresponding as toitsobjeot with the lead given a slide-valve in a steam-engine,'and itinsures a prompt and, timely actionon the power-piston at the turni Toreduce as much aspossible the loss of live power by countering-points ofthe latter.

actionof the-air on the downstrokeof the up per pistomwe providerelief-ports 32 32, which 1 are uncovered at the same moment that thepower-piston arrives at its highest position,

piston. The air thus escaped passes down in pipes 33,-during which timeit becomes cooled, and lifting check -valves 34L it enters the lower apart of thecylinderto be reheated. By reason of said check-valves no aircan pass out the; other way. As in practice the loss of-air can not-beavoided it is necessary that a vacuum valve 36 be provided, beingsubstantially a check-valve, which permits the influx of air, butno'escape outwardly. The quantity of air supply may be regulated orentirely shut off by means of a cock 37. The power of the motor istransmitted from its main shaft 26, at the outer end of which connectionis made by means of a crank 38, or cog-wheel, or otherwise, tomeetparticular requirements. When driving a pump, the same may rest on abracket 39, in which case the water pumped may also be used to cool theupper part of the cylinder, entering the jacket 31 at 40 and passing outat 41. Proper provision to prevent the escape of air should be appliedwherever necessary, for which purpose piston 13 has packing-rings and astuffing-box 42 between it and the piston-rod of the lower piston whereit passes'through the upper piston.

Having described our invention, we claim as new- I V Ina hot air engine,the combination'of a cylinder, apower-and adisplacer piston reciprocating therein, the latter'piston not completely fitting fthecylinder, a mainshaft to which the two pistons are operatively connected,pressure-relief ports 32 so located in the cylinder as to be uncoveredwhen the power-piston is at :its'highest position, air-return pipesconnecting with said ports and check-valves 34 therein.

In testimony whereof we hereuntoaffix our signaturesin presence-of twowitnesses.

EMIL MIHSBACH. ANTON GROESOHEL. Witnesses:

0. 'SPENGEL, ARTHUR KLINE.

